That isn't just a wart, it is definitely an infection of some sort. The vet should see that and antibiotics need to be used, not just a cream, but injectible or oral. It looks to me like an infected bite wound. The nose is a popular place for bunnies to bite each other. Other possibilities include a tumor of some sort as well. It could be a wart but the irritated skin around it means that it needs some vet attention, plus if it gets bigger she may have trouble breathing.